Multiplication-stimulating activity-induced alkalinization of canine renal proximal tubular cells

Journal Article · Wed Nov 05 04:00:00 EST 1986 · J. Biol. Chem.; (United States)

OSTI ID:7093642

Mellas, J; Gavin, III, J R; Hammerman, M R

The actions of a variety of polypeptide growth factors on isolated cells are thought to be initiated by stimulation of Na/sup +/-H/sup +/ exchange across the plasma membranes of the cells resulting in intracellular alkalinization. To determine whether insulin-like growth factors (IGFs) exert actions through such a mechanism, the authors incubated suspensions of canine renal proximal tubular segments with insulin or IGF I or with multiplication-stimulating activity (MSA)/IGF II. Changes in intracellular pH were detected by measurements of the distribution of (/sup 14/C)5,5-dimethoxazolidine-2,4-dione. Incubation of segments with 10/sup +9/ M MSA under conditions such that extracellular (Na/sup +/)> intracellular (Na/sup +/) effected intracellular alkalinization detectable within 1-2 min. Alkalinization was not observed under conditions where this gradient was not present. Alkalinization was not prevented by inclusion of 1mM 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid or 1 mM ouabain in incubations, but was inhibited by amiloride. Incubation of proximal tubular segments with as little as 10/sup +11/ M MSA effected intracellular alkalinization. Incubation with as much as 10/sup -6/ M insulin or IGF I did not. Our findings are consistent with an action of MSA/IGF II to stimulate Na/sup +/-H/sup +/ exchange across the plasma membrane of the renal proximal tubular cell. It is possible that the stimulation represents a mechanism by which actions of IGF II are initiated in growth factor-sensitive cells.

• Research Organization: Washington Univ. School of Medicine, Louis, MO
• OSTI ID: 7093642
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 261:31; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ANIMAL CELLS
ANIMALS
AZOLES
BARYONS
BIOCHEMISTRY
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CATIONS
CELL PROLIFERATION
CHARGED PARTICLES
CHEMISTRY
DOGS
DRUGS
ELEMENTARY PARTICLES
FERMIONS
GLYCOSIDES
GROWTH
HADRONS
HETEROCYCLIC COMPOUNDS
HORMONES
INSULIN
IONS
KIDNEYS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE TRANSPORT
NUCLEONS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OUABAIN
PEPTIDE HORMONES
PH VALUE
PROTEINS
PROTONS
SODIUM COMPOUNDS
STROPHANTHINS
VERTEBRATES